Automatic stop mechanism for sewing machines



Jan. 26, 1954 J F, JECKERT 2,667,134

AUTOMATIC STOP MECHANISM FOR SEWING MACHINES Filed Dec. 19, 1950 2 Sheets-Sheet 1 IN V EN TOR. 1/0 JEPH F. I/EC/(EIPT A 7 TORNEY Jan. 26, 1954 J JECKERT AUTOMATIC STOP MECHANISM FOR SEWING MACHINES Filed Dec. 19, 1950 2 Sheets-Sheet 2 INVENTOR. Moss/w Edie/raw BY 04% A rromwsr Patented Jan. 26, 1954 AUTOMATIC STOP MECHANISM FOR SEWING MACHINES Joseph F. Jeckert, Clifton, N. J. Leonora Jeckert, executrix' of said Joseph F. Jeckert, deceased; assignor to Helen Alnor Jeckert, CliftomgN. J.

Application'December 19, 1950, Serial No. 201,624;

This invention relates to an automatic stop mechanism for sewing machines and has for its object to provide amec'hanisn'r for automatically stopping a sewing machine when either the bottom or top thread breaks or runs out.

Another object of the invention is to provide a stop mechanism which may be readilyactuated by the operator, as by means of aclutch operating lever.

With the above-and otherobjects in view, this invention consists of the-novelfeatures'of construction, combination and arrangement of parts, hereinafter fully described, claimed and illustrated in the accompanying drawings forming part of this application, and in which similar characters of reference indicate corresponding parts in all views, and in which:

Figure 1 is a front elevation of a sewing machine embodying the present invention.

Figure 2 is a top view thereof.

Figure 3 is a wiring diagram showing the electrical connections.

Figure 4 is a vertical section of the clutch mechanism, while Figure 5 is a view on the line 55 of Figure 4.

Referring more particularly to the drawing, the numeral It indicates the head of the machine having the usual presser foot bar II and needle bar |2 driven by a suitable mechanism (not shown).

A pulley l3 driven by the usual motor (not shown) is mounted on a co-axial shaft |4 having ball bearings l5; said shaft M has a tubular extension |5 which receives the end of the drive shaft 2|, and on said tubular extension a clutch sleeve member ii is slidably mounted; a disc I8 extends from said clutch sleeve member I1 and carries on its periphery a friction member I9 adapted to engage a second disc 20 attached to the pulley I3, so that said pulley |3, shaft I4 and the extension I6 of the shaft l4 will rotate as a unit to drive shaft 2|, which, in turn, actuates the needle bar l2.

A deep grooved clutch pulley 22, is slidably mounted upon the clutch sleeve member said clutch pulley 22 is urged away from the disc |8 by a spring 23 and has an operating lever 24 pivoted at 25 in a clutch housing 245; the said housing has mounted thereon a switch 21 formed with a leaf 28, which extends into the path of a rod 29 fixedly secured to a lever 30, and said lever, in turn, extends into the path of the pole of an electromagnet 3|. The lever 30 has ears 32 pivoted at 33 on a block 34 fastened to the housing 26, said block 34 has a spring 35 interposed 2. 7 between it and the lever 30,;at: the" other end. The block 34 has further arr-adjustable stop 36 whereby to limit the movement of the lever 3|] on its pivot 33, when the electrcmagn'et is deenergized.

The operating lever 24 has a yoke 24' on its upper end provided withl-a cross-fbar 3'l', which extends in the path of an angular: extension 38 of the lever 30; the purpose-ofthisyis' to'retain the clutch disc H3 in contact; with thedisc 29; upon energizing the. magnet-31,; the; lever 39, will be attracted and pulled down at which time the angular extension 38 will be lifted out of engagement with the cross bar 31 and, due to this movement, the rod 29 moves out of engagement with the leaf 28 of the switch 2'! to open the circuit.

Mounted upon a sewing machine arm 39 is an angular support 40 which carries a tension device 4|, arranged on a shaft 42, the latter carries an arm 43 provided on its end with a contact 44; the shaft 42 has a thread guide 45 adapted to rotate on a sleeve 46, the movement of said guide 45 is limited by a stop pin 41. A perforated rod 48 fixed to the upright 40' of the angular support 40 serves to accommodate the thread which passes through said perforated rod.

A flat support 44 is attached to the machine head at the top thereof and this is provided with a vertical plate 40, and on this vertical plate a shaft 42 is mounted to turn, and on this shaft a V-grooved pulley or thread tensioning device 4| is mounted. From the shaft 42a thread tensioning arm 45 extends, which is provided with the usual terminal thread loop. On the end of the shaft 42 an arm 43 is mounted, and the outer end of this arm is provided with a contact element 44, which engages the contact 49, mounted on the support plate 49'. A stop pin 4'! is provided for limiting the play of the tensioning arm 45. The tensioning pulley or spool 4| is supported in line with a horizontal arm or bar 48, the inner end of which is secured to the plate 40', and this arm or bar is formed with a single hole through which the thread extends.

The arm or bar 48 is located above the horizontal plane of the shaft 42, and the thread passes under the tensioning spool or pulley 4| and thence through the hole of the arm or bar 48, and the tension of the thread acts to hold the contact 44 of the arm 43 normally elevated above the sta-- tionary contact 49. When the thread breaks the arm 43 drops and the contact 44 engages the contact 49, which closes the circuit through the magnet 3|, and as this magnet is energized the lever 30 is attracted by the pole of the magnet,

and the lug or finger 38 of this lever 80 is disengaged from the cross bar 31 of the yoke 24'. When this takes place the spring 23 acts on the yoke lever 24 to cause the spanner yoke to shift the pulley 22 away from the disc 20, and as the pulley 22 is shifted the disk I8 is displaced from the disc 20, thus disengaging the shaft 21 from the motor pulley I3.

As the lever 30 is actuated by the magnet 3| the bar 20 attached to the lever 30 engages the switch arm or leaf 28 and operates the switch 21, to break the circuit through the motor which drives the pulley I3, thus stopping the rotation of the pulley I3.

My improved whirl stop mechanism is adapted to control all types of sewing machines, home and industrial, and provides'an automatic control for stopping a machine when the thread breaks, which does not call for changes in the mechanism of the sewing machine itself.

It is obvious that changes may be made in the form, construction and arrangement of the several parts, as shown, within the scope of the appended claim, without departing from 'the spirit of the invention, and I do not, therefore, wish to limit myself to the exact construction shown and described herein.

What I claim, as new, and desire to secure by Letters Patent of the United States, is:

In combination with a sewing machine having an operating shaft and needle reciprocating mechanism driven thereby, an extension for the drive shaft having a motor driven pulley mounted to rotate on said extension and a clutch disc carried by said motor driven pulley, a companion clutch disc slidable on said shaft extension, a pulley mounted on said companion clutch disc to move therewith, a spanner yoke having engagement with the pulley last-named, a lever connected with said spanner yoke, a spring engaging the lever to actuate the yoke in one direction, a lever pivoted to swing close to the yoke and provided with a finger to engage the yoke to hold the clutch discs normally engaged, a magnet for actuating the lever, a switch having circuit connections with the magnet to energize the same, said switch having a movable arm, and thread tensioning mean for holding said arm in an open circuit position, whereby said switch will close the circuit through the magnet when the thread breaks, to cause the movable clutch disc to disengage from the other clutch disc.

JOSEPH F. JECKERT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,052,955 Poirier Feb. 11, 1913 1,241,710 Corrall et al. Oct. 2, 1917 1,453,202 Stevens Apr. 24, 1923 1,731,001 Gail Oct. 8, 1929 2,251,368 Moser Aug. 5, 1941 

